Crawley Library Building
A full case study of the Crawley Library is available here.
Professor Rajat Gupta, Oxford Brookes Enterprises Ltd.
Building type, sector and stage
Non-domestic, new build, public service, in operation, South East
Biomass, thermal mass, mixed mode ventilation, BMS, solar thermal, library
Crawley library is an award winning exemplar of sustainable public building design, providing library, registrar and social service facilities. Facing onto a new public square, the four-storey building has a stone and glass façade, with each floor providing a cantilever over the level below, shading the south and west facades.
Occupied in December 2008, best practice sustainability principles used includes exposed thermal mass, a daylight strategy, natural stack effect, a mixed mode ventilation system, an efficient biomass boiler and solar water heating.
The design aspirations were high with 60% reduction in carbon emissions over requirements of the 2006 Building Regulations, BREEAM ‘very good' and EPC rating of ‘A'. The actual performance in-use resulted in a DEC of ‘D' for 2009 and 2010.
Initial findings of the BPE study identified a lack of understanding of the environmental control strategy, BMS and sub-metering underpinning high energy use in operation, which can be attributed to changes in FM staff and a poor handover.
Additionally the biomass boiler was out of service for two years due to various issues including poor commissioning, difficulties associated with cleaning, mechanical issues with woodchip conveyor and delay in appointment of service provider due to higher than expected maintenance costs.
The occupancy survey revealed staff members appreciated the good lighting within the building and described the modern design as attractive, open and airy. This is epitomised in the library atrium with natural daylight and feature staircase in acoustic timber panelling.
The survey also revealed ventilation problems and overheating in several areas in the summer months, which is coupled with staff frustrations with the usability of windows and environmental controls.
The BPE study looks to address the issues identified and provide feedback to the building users and delivery team. The disconnect of information to FM staff is to be addressed with additional training, to enable management and control of the building systems to reduce energy consumption and realign with design intentions.
|Floor area (GIA)||4468 m2 (2678 m2 library, 502 m2 registrar, 378 m2 public social services and 910 m2 administration)|
|Floor area (Treated)||4146 m2|
|Air permeability||4.88 m3/m2/h @ 50Pa|
|Building Regs estimate of CO2||12.14 kgCO2/m2/yr|
|BREEAM rating||Very Good, potentially Excellent|
|EPC rating||A (25)|
|DEC rating||DEC 2009 D(80), DEC 2010 D(90)|
|Measured electricity use||163 kWh/m2/yr*|
|Measured gas use||38 kWh/m2/yr*|
|Measured CO2 emissions||93 kgCO2/m2/yr*|
|Total CO2 emissions||413,223 kgCO2/yr*|
|Occupancy pattern||1175 (total of maximum library, registration service and social services occupancy)|
*Estimated from limited data (due to unreliable metering)